These are my suggestions:

Cruiser with ltc sci: Ambassador class http://www.ex-astris-scientia.org/ar...ambassador.htm

Escort with ltc eng: New Orleans class http://www.ex-astris-scientia.org/ar...neworleans.htm

Science with ltc tac: Springfield class http://www.ex-astris-scientia.org/ar...pringfield.htm